Abstract The wetting of coal pores by water has an observable influence on the flotation recovery of combustible matter from fine coal resources. In this investigation, low-field nuclear magnetic resonance (LF-NMR) was employed to measure the porosity of coal pores after various pre-conditioning times; the water wetting degree of coal pores was then characterized using this porosity data. The water wetting percentage of coal pores was calculated by using the ratio of the measured porosity to the total porosity (obtained from a water-saturated coal sample). The water-saturated coal sample had a total porosity of 23.22%, which was dominated by mesopores and macropores. The measured porosity of the coal surface increased from 11.33% to 15.37% as the pre-conditioning time was increased from 0 to 10 min, and the flotation recovery was reduced from 65.23% to 21.58%. The water wetting degree of the macropores was found to have a stronger negative effect on the coal flotation than that of the mesopores. The larger pores were more easily wetted by water than the smaller pores, resulting in the formation of a thick hydration layer on the coal surface, which reduced the floatability of coal particles. Additionally, the negative linear correlation between the water wetting percentage of the coal pores and the flotation recovery was determined to elucidate the effects of the water wetting of the coal pores on its flotation behavior.

中文翻译：

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LF-NMR表征的煤孔隙润湿及其与浮选回收率的关系

摘要 水对煤孔隙的润湿对粉煤资源中可燃物的浮选回收具有明显的影响。本研究采用低场核磁共振（LF-NMR）测量不同预处理时间后煤孔隙的孔隙度；然后使用该孔隙度数据表征煤孔隙的水润湿程度。煤孔隙的水润湿百分比通过使用测量的孔隙率与总孔隙率（从水饱和煤样品获得）的比率计算。含水饱和煤样总孔隙率为23.22%，以中孔和大孔为主。随着预处理时间从 0 分钟增加到 10 分钟，煤表面的实测孔隙度从 11.33% 增加到 15.37%，浮选回收率从 65 降低。23% 到 21.58%。发现大孔的水润湿度对煤浮选的负面影响比中孔的大。较大的孔隙比较小的孔隙更容易被水润湿，导致煤表面形成较厚的水化层，降低了煤颗粒的可浮性。此外，确定了煤孔隙的水润湿百分比与浮选回收率之间的负线性相关性，以阐明煤孔隙的水润湿对其浮选行为的影响。导致煤表面形成较厚的水化层，降低了煤颗粒的可浮性。此外，确定了煤孔隙的水润湿百分比与浮选回收率之间的负线性相关性，以阐明煤孔隙的水润湿对其浮选行为的影响。导致煤表面形成较厚的水化层，降低了煤颗粒的可浮性。此外，确定了煤孔隙的水润湿百分比与浮选回收率之间的负线性相关性，以阐明煤孔隙的水润湿对其浮选行为的影响。